Many watercraft are propelled by outdrives such as outboard engines, stern drives and pod drives for example. To steer the watercraft, the outdrives are pivoted relative to the rest of the watercraft. This is often achieved by hydraulic steering actuators. To control the steering of the watercraft, the driver turns a helm.
In some hydraulic steering systems, turning the helm pushes hydraulic fluid in one direction to the hydraulic steering actuators which causes them to steer the outdrives. In such systems, the helm acts as a hydraulic pump and is known as a hydraulic helm.
In other hydraulic steering systems, a helm position sensor senses the position of the helm and sends a signal representative of this position to a steering controller. Based at least on this signal, the steering controller sends signals to hydraulic pumps and, in some cases, valves to control the supply of hydraulic fluid to the hydraulic steering actuators in order to achieve the desired steering. These systems are known as steer-by-wire systems.
To facilitate docking maneuvers, some watercraft having a steer-by-wire system are provided with an auxiliary steering input device such as a joystick. To use the joystick, the driver first switches to a docking mode. This can be done by pressing a button or simply in response to movement of the joystick. Other conditions may have to be met prior to switching to the docking mode, such as being at a low watercraft speed for example. Once in the docking mode, the steering controller uses signals received from a joystick position sensor sensing a position of the joystick to control movement of the watercraft. In the docking mode, signals from the helm position sensor are not used. As such turning the helm when in the docking mode has no effect on the steering of the watercraft. Based on the signal received from the joystick, the steering controller sends signals to hydraulic pumps and valves to control the supply of hydraulic fluid to the hydraulic steering actuators in order to achieve the desired movement of the watercraft. In the docking mode, the position of the joystick also determines the thrust generated by each outdrive. In the docking mode, when two outdrives are provided, the two outdrives can be steered in opposite directions and can also generate thrust in opposite directions. As such, in the docking mode, the watercraft can translate in any direction, can be steered in a motion similar to the one that occurs when the helm is used, and can pivot about itself. As would be understood, these maneuvers make docking of the watercraft easier.
In a watercraft having a steering-by-wire system, providing a joystick to operate the watercraft in a docking mode is relatively simple. A suitable steering controller is provided which uses the signals from the helm position sensor or the joystick position sensor to control the watercraft depending on the selected steering mode.
As would be understood, it would be advantageous to provide an auxiliary steering device and provide a docking mode on watercraft having a hydraulic helm. However, simply adding a joystick and suitable controller to such a watercraft does not provide a functional auxiliary steering device with a docking mode, since turning the helm results in steering of the outdrives.
There is therefore a desire for a watercraft having a hydraulic helm and an auxiliary steering device to provide a docking mode.
Also, should the steering system cease operation when in the docking mode, it is possible that the outdrives could remain in a splayed configuration. In such situations, conventional steer-by-wire systems require that the operator disengages one or both outdrives from the steering system and then manually pushing one or both outdrives until they are properly aligned. As will be appreciated, this is inconvenient.
Outdrives can also become misaligned over time, which would require a similar solution to be used.
There is therefore a desire for a watercraft having a steering system that facilitates the realignment of the outdrives should they become misaligned.